Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
  • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
  • C08G69/32—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound

Definitions

• the present invention relates to aromatic polyamides which have high temperature resistance and good mechanical properties, and which are thermoplastically processible.
• X and Y alternatively stand For an ether and a sulfonyl group, and Ar, Ar' and Ar" stand independently of one another for the para- and meta- phenylene group.
• Aromatic polyamides can also be prepared by the reaction of aromatic dicarboxylic acids with aromatic diisocyanates (German Pat. No. 19 28 435) and by reacting aromatic dicarboxylic acid diaryl esters with aromatic diamines.
• This process has the disadvantage that it calls for the use of activated, hard-to-handle monomers, such as dicarboxylic acid chlorides.
• N-methyl acid amides particularly N-methylpyrrolidone
• dipolar aprotic solvents such as dimethylsulfoxide
• the phosphite to be used must contain aryl groups and should preferably be a triphenyl phosphite;
• the aryl phosphites must be used in at least such quantities that for each mole of amide to be substituted, one mole of a compound containing the grouping
• U.S. Pat. No. 3,109,836 discloses a process for producing polyamides with repeating units of (CO--Ar--NH) that consists of heating acetamidobenzoic acid for three hours in a vacuum at 200° to 300° C.
• aromatic polyamides can be produced by amidation of acylated aromatic amines in the melt. Apart from the fact that such a proceeding would require the prior production of the acylated amines, the results obtained with this process must be considered highly unsatisfactory. In order to improve processibility, the starting compounds are not purely aromatic compounds, but rather a mixture including aliphatic compounds. The diamines are only partially, not completely acylated. Finally, acetic acid, an acetic anhydride, dimethyl acetamide or another agent is added to the reaction melt to improve the flowability. (See Keske et al., Polymer Prepr. 25, Part XXV, p. 25 (1984) and U.S. Pat. No. 3,654,227).
• one object of the present invention is to provide a process for producing thermoplastic aromatic polyamides by a melt polycondensation method while avoiding the production of heavily colored compounds.
• Ar is meta-phenylene, para-phenylene;
• Z is --O--, --S--, --SO 2 --, --CO-- or --C(CH 3 ) 2 -- or mixtures thereof;
• q is 0 or 1; and
• r is 0, 1 or 2;
• isophthalic acid which may be replaced up to 60 mole % by terephthalic acid, wherein said isophthalic acid and said terephthalic acid may be substituted by at least one C 1 -C 6 alkyl radical, alkyl-or aryl-substituted phenyl radical, C 1 -C 6 alkoxy radical, phenoxy radical in which the phenyl ring can be alkyl- or aryl-substituted, or a halogen;
• the process for producing the polyamides of the present invention consists of reacting an approximately equimolar mixture of aromatic dicarboxylic acid and aromatic diamine in the presence of at least the minimum catalytically effective quantity of triphenylphosphite or an acid derived from phosphorus with the formula H 3 PO n where 2 ⁇ n ⁇ 4 or a catalytically effective quantity of a mixture of the abovementioned phosphorus compounds and a 4-dialkylaminopyridine in the melt at temperatures between 200° and 380° C.
• the molecular weight of the polyamides obtained lies between 10,000 and 200,000, preferably between 20,000 and 70,000.
• aromatic dicarboxylic acids or mixtures thereof may be used according to the invention:
• Ar metal-phenylene or para-phenylene
• A --O--, --S--, --SO 2 --, --SO--or a single bond
• p 0 or 1.
• aromatic diamines or mixtures thereof may be used according to the invention:
• Ar' and Ar" stand for meta- or in particular para-phenylene radicals; particularly:
• Ar metal-phenylene, para-phenylene
• Z at least one type of radical selected from the group --O--, --S--, --SO 2 --, --CO--, or --C(CH 3 ) 2
• q 0 or 1
• r 0, 1 or 2.
• aromatic diamines 0.95 to 1.05 mole, preferably 1.0 mole of aromatic dicarboxylic acid is used.
• aromatic dicarboxylic acids are reacted with the diamines in the presence of a catalytic quantity of a phosphorus-containing compound or in the presence of a catalytic quantity of a mixture of said phosphorus containing compound and a 4-dialkylaminopyridine.
• Suitable phosphorus-containing compounds are triphenylphosphite, hypophosphorous acid, phosphorous acid and phosphoric acid.
• the 4-dialkylaminopyridines used as a co-catalyst have the following structure: ##STR4## where R 1 and R 2 either stand independently of one another for a C 1 -C 10 alkyl radical or together with the amino nitrogen can form a pyrrolidine or alkyl piperidine ring.
• Preferred 4-dialkylaminopyrrolines are: 4-dimethylaminopyridine, 4-dibutylaminopyridine, 4-di-n-hexylaminopyridine, and 4-piperidinylpyridine.
• the pyridine derivatives can be produced according to Synthesis 844 (1978).
• High-boiling organic bases with tertiary nitrogen atoms can also be used as the co-catalyst, such as isoquinoline or quinoline, and inorganic basic salts, particularly alkali and alkaline earth carbonates, such as calcium carbonate.
• the operation is performed under inert gas at normal pressure. It is possible however, when desirable for one reason or another, to work at a pressure slightly above or below normal.
• the reaction times required to obtain sufficiently high molecular weight products are between 1 and 4 hours.
• the polycondensation process is performed in the melt at temperatures between 200° and 380° C., preferable between 250° and 350° C.
• Three preferred embodiments of the process are as follows:
• a powdered mixture of the reactants and catalysts is processed in a kneader with a gradual increase in temperature from 220° to 290° C., until the water produced by condensation is eliminated.
• a powdered mixture of the components is fed into the apparatus, and the reaction water is completely eliminated by suitable adjustment of temperature.
• Embodiment (1) it is possible as in Embodiment (1) to transform the starting products first to a precondensate at a temperature of from 200° to 280° C. and then to further condense the precondensate in a kneader or extruder.
• temperatures of from 280° to 350° C., preferably from 290° to 330° C. will then normally be required. This embodiment is particularly preferred.
• the catalyst generally remains in the product. If it is desirable, however, it may be removed by dissolving and precipitating the reaction product in a suitable solvent, such as N-methylpyrrolidone.
• Embodiment 1 In order to produce sufficiently high-molecular-weight products, it is necessary to remove the water formed during polycondensation from the reaction system. In Embodiment 1), this is accomplished by passing inert gas over or through it. The use of a vacuum is also effective.
• the resulting products can be fabricated into films by pressing at high temperature ( >200° C.).
• Organic solutions of the polyamides in suitable aprotic polar solvents may also be made into cast sheets in a conventional manner.
• the viscosity number J of the polyamides obtained which constitutes a measure of the relative molar mass is determined in the following tests in mixtures of 1,2-dichlorobenzene and phenol in the volume ratio 1:1 as per DIN (German Industrial Standard) 53,728.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyamides (AREA)

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• 1986
  • 1986-03-18 DE DE19863609011 patent/DE3609011A1/de not_active Withdrawn
• 1987
  • 1987-01-22 AT AT87100827T patent/ATE45369T1/de not_active IP Right Cessation
  • 1987-01-22 DE DE8787100827T patent/DE3760423D1/de not_active Expired
  • 1987-01-22 EP EP87100827A patent/EP0237722B1/fr not_active Expired
  • 1987-02-13 US US07/014,841 patent/US4749768A/en not_active Expired - Fee Related
  • 1987-03-16 JP JP62060890A patent/JPS62225530A/ja active Pending

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